1. Field of the Invention
The present invention relates to an optical waveguide film that guides light as waveguide light and a light transmission and reception module using the film, that is used for mobile appliance.
2. Description of the Related Art
Examples of an optical waveguide film producing method include: (1) a method of impregnating films with monomer, selectively exposing cores and changing reflectance so as to laminate films (selective polymerization); (2) a method of applying a core layer and a cladding layer so as to form a cladding portion using reactive ion etching (RIE method); (3) a method using a lithography method of performing exposure and development using an ultraviolet curable resin where a photosensitive material is added to a macromolecular material (direct exposing method); (4) a method using injection; and (5) a method of applying a core layer and a cladding layer, exposing a core portion so as to change reflectance of the core portion (photo-breaching method).
However, the selective polymerization (1) has a problem of lamination, the cost is expensive in the methods (2) and (3) as the photolithography method is used, and an obtained core diameter may be inaccurate in the method (4). The method (5) cannot obtain sufficient difference in reflectance between the core layer and the cladding layer.
At present, only the methods (2) and (3) are practical with excellent performance, but the cost is expensive. In addition, all the methods (1) to (5) cannot be applied to formation of a macromolecular waveguide on a flexible plastic base material with a large area.
A waveguide copying technique, which is proposed by the present inventors, uses a micromold method to which the lithography technique is applied. With this method, a macromolecular waveguide can be simply copied on a flexible plastic base material with a large area, and thus this method has excellent mass productivity.
Recently, optical wiring is noted in order to improve an operating speed and an integration degree in IC technique and LSI technique. The optical wiring is realized between devices, between boards and between chips in the devices instead of electric wiring with high density. A flexible optical waveguide substrate is proposed in order to realize the optical wiring.
In Japanese Patent Application Laid-Open (JP-A) No. 4-281406, for example, after a reinforcing member is formed on a base material, an optical waveguide film is formed thereon, and the base material is removed selectively except for a portion which is desired to be reinforced so that a flexible optical waveguide with the reinforced portion is formed.
JP-A No. 2000-235127 describes a photoelectronic integrated circuit where a macromolecular optical waveguide circuit is assembled directly on a photoelectric fusion circuit board where electronic elements and optical elements are integrated.
When the above elements are packaged in the optical wiring and can be incorporated into a device, the assembling flexibility of the optical wiring can be increased. As a result, a compact device can be manufactured.
On the other hand, as a structure where a power supply wire is provided to an optical fiber, JP-A No. 2005-37592 discloses an example where a power is supplied by using a metal loading optical fiber.
The optical waveguide proposed in JP-A No. 2005-37592 or the like is, however, mostly operated as a stand-alone optical waveguide, and an optical waveguide where electric wiring for supplying a power to a mobile appliance and an optical waveguide are included is not proposed yet.
The present invention provides an optical waveguide film which enables a power supply at an extremely low cost, and a light transmission and reception module using this film.